Question

Answer me 51 & 53 questions

Answer 1

Here is your answer :

Q. 51

Given,

⇒ Initial Velocity ( u ) = 0

⇒ Acceleration due to gravity ( g ) = 9.8 m/s² [ Since , the body is thrown downward ]

⇒ Final Velocity = ?

Now,

Let the final velocity is 'v' and displacement is 'h'.

It's given that Final Velocity and displacement is numerically same.

So,

⇒ v = h

We know that,

⇒ v² = u² + 2gh

⇒ v² = u² + 2gv

⇒ v² = 0² + 2 × ( 9.8 ) × v

⇒ v² = 0 + 19.6 v

⇒ v² = 19.6 v

⇒ v² ÷ v = 19.6

•°• v = 19.6

Since, initial velocity and acceleration is in its S.I unit, so Final Velocity must be in its S.I unit.

Hence , Final Velocity = 19.6 m/s

2 ) 19.6 m/s ✓

Q. 53

Given,

⇒ Final Velocity ( v ) = 0 [ Since, the body reaches at its maximum point ]


⇒ Time ( t ) = 2 s

⇒ Acceleration due to gravity ( g ) = -9.8 m/s² [ Since, the body is thrown Upward ]

⇒ Initial Velocity ( u ) = ?

We know that,


⇒ v = u + gt

⇒ 0 = u + ( -9.8 m/s² ) 2s

⇒ 0 = u - 19.6 m/s

⇒ - u = - 19.6 m/s

•°• u = 19.6 m/s

2 ) 19.6 m/s ✓

Answer 2

${\bold{\huge{\green{\underline{Answer}}}}}$

$\bf\implies\:Initial\:velocity\:=0$

$\bf\implies\:Final\: velocity\:=\:?$

$\bf\implies\:v\:=\:h$

$<b><u> we know that:$

$\large\bf\implies\:v^2=u^2+2gh$

$\large\bf\implies\:v^2=u^2+2gv$

$\large\bf\implies\:{v^2}=19.6\:{v}$

$\large\bf\implies\dfrac{\cancel{v^2}}{\cancel{v}}=19.6$

$\large\bf\implies\:v=19.6\:m/s$